Means for controlling gas velocity in reverberatory furnaces.



PATBNTED MAY l, 1906. E. ELDRBD.

B MEANS POR OONTROLLING GAS VELOCITY 1N REVBRBBRATORY FU RNACES.

APPLICATION FILED PBB.8. 1905.

2 SHEETS-SHEET l.l

I gig-dot` No. 819,046. PATBNTBD MAY 1, 1906.

B.E.ELDRED. MEANS PORGGNTROLLING GAS VELOCITY 1N RBVBRBBRATORY PURNAGBS.

APPLICATION FILED TEB.8. 1905.

2 SHEETS-SHEET 2.

Umfrnn sTATn's PATENT orifice@ BYRON-E. ELDRED, OF BRONXVILLE, NEW YORK, ASSh'NOR TO COMBUS- TION UTILTTIES COMPANY, OF NEWY YORK, N. Y., A CORPORATION OF NEW YORK.

MEANS FOR CONTROLUNG GAS VELOCITY IN REVERBERATORY FURNACES.

Speciticaton of Letters Patent.

Patented May 1, 1906.

Application filed February 8,1905. Serial No. 244,738.

T all when', it muy concern:

Be it known that I, BYRON E. Emmen, a citizen of the United States, residing at Bronxville, county of Vest-chestcr, State of New York, have invented certain new and useful Improvements in Means for Control-l ling Gas Velocity in Reverberatory Furnaces,

of which the following specification and accompanying drawings illustrate one form of 1o the invention which l now regard as the best out of the various forms in which the invention may be embodied.

This invention relates to revcrberatory furnaces in which several lire-boxes are employed, distributed at intervals along and opening into the hearth-ch amber wherein the materials under treatment are roasted or calciued or subjected to heating operations of a like character. lieretofore inadequate provision has been made fpr regulating the velocity of the l'lame-current--tluit is to say, whereas each succeeding fire-box, reckoning in a direction toward the chimney, adds its flame increment to the total quantity of gases passing through the hearth-chamber there is commonly no provision made in the ordinary straight-line furnaces for regulatingr the consequent velocity of the gases in order to secure their maximum eli'ect upon the materials under treatment. The consequence is that while at points remote from the chimney the flame-current may he travelii'ifbT at a proper velocity to yield up its heat to the materials in an effective manner, at points nearer to the chimney, where the rases have received an increment by the addition of other flamecurrents, the current must travel at a faster rate, since its increase of volume can only be accommodated longitudinally of the combustion-chamber. Hence in that locality they do not roperly Vyield their 'neat 'to the materials. Vith each successive increment of volume the velocity increases. ll' the chimneydamper be adjusted to diminish thevelooity of the gasesnearcstthe chinm to the proper point, those in lthe more remote portions of the furnace will have iiisuii'icieut velocity, and the fires at those more remote points `will not draw properly.

llhe forerroiuev del'ectifr (.:onditimis are observable when ordinarylires are employe-:lon furnaces oi' the character s1. ated. They are perhaps exaggerated when the lires are opei'- ated by the process described in my Patent No. 692,257. It should be mentioned that the process of said patent is applied with great advantage to reverbcratory operations, owing to the cooler lires, voluminous flame brought close to the materials, great length of flame, and fuel economy, and when so applied the process constitutes an invention whichI have made the subject of a separate application, Serial No. 223,880, September 9, 1904. The increment of volume from each succeeding fire-box is here very noticeable, and there is, when the flame is allowed its natural development, probably less theoretical contraction of the gas-current from the more orless abru t transition from the monoxid condition to t e dioxid condition characteristic of an ordinary flame.

This invention furnishes n remedy for the defective conditions above mentioned bysuccessivelyin creasing the cross-sectional area of the gas-current in approaching the chimney at or just before the points at which the successive increases of volume takrl .la'v i' the additional fire-boxes. .lf the im cross-sectional area be made proportional to the increase of' `volinne, the veler-.ity oi' fh"- gas-current will remain the same as or. o ze. l find that this result can bc attained. in :i s. ple manner by increasing; the aperture'cf th.:` hearth-cham ber at the desired oi nt or points.

My invention consists in a urnace having 5 this characteristic construction; and it fu@ ther consists in the novel method of treating the gas-current so that its velocity remains the same, or substantially so, with each suci-.essive increase in voliune.

In the drawings, Figure 1 represents a longitudinal section of an ore-roasting furnace construction and arranged accord i ng to my invention and adapted to carry out the aforesaid process. Fig. 2 represents a top plan view partly in section. llig. 3 represents a section on line $5 3 ol Fig. 2, enlarred.

The same reference cnararders represent the semeparts in all the igures.

Tn thi,` drawings, 10 indicates the hearthrhaniber or combuslion-chamber, having;v a stack il at one end und fire-boxes 12 l2 opening; into said chamber at different points along its length and arranged alternately on ooposite sides. I do not confine myself to tnis exact arrangement, as the fire-boxes may IOO `to each fire-box.

be in pairs onopposite sides, or-'may be arranged along one side only.

13 indicates an endless conveyerV carrying the usual rabbles or plows 14 for stirring the material and producing a travel thereof .in a direction opposite to the direction of travel of the llame. At or about the points where the second and third fire-boxes 12, reckoning from left to right,`open into the chamber 10, the roof thereof is offset or raised to an lncreased distance above the hearth 15, as indicated at 1.6 16. At these points also within the hearth-chamber are arranged transverse partitions or flame septa 17 17, beneath .which the entering flame-currents pass into the body of the vhearth-chamber, While the gases from more remote points largely pass above these septa. While these septa aid in the separation of the currents at the points of entry of fresh currents, l do not limit myself to the provision of a septum at each oint of entry and may omit the septa altoget er.

18 is a pipe leading back from the stack 1 1 at a point below the damper 19 and branchingto the ash-pits of the several fire-boxes .1.2, said pipe` containing a fan-blower 2() and havlng an air-inlet 21 and suitable valves or ates for regulating theA relative quantities of fresh air and stack-gases in the draft sup lied By this means each e is supplied by a draft current, preferably forced or artificially accelerated, containino' predetermined quantities of free oxygen and neutral diluent, whereby the fires furnish lon@ slow-burning voluminous flames, as descri ed in my aforesaid patent and application.

ln operation the fires are preferably started'in the more remote fire-boxes first, and then successively in those nearer the stack after 'the lirst fires have warmed up the vicinity which they affect. By making the increasel in capacity of the furnace at each point of increment correspond to that increment, the velocity of the gases remains uniform, givin a uniform period ofheating effeet tothe i ames from the several fire-boxes and enabling the drafts 0f the several fires to be regulated uniformly by the single damper 19. The volume of llame can be regulated by varying the proportion or velocity of the stack-gas current, and the apparatus can be adjusted to compensate for the naturally heavier draft nearer the chimney, due to frictional and heat effects. l do not broadly limit'myself to the expansion of the gases in any single direction, as this expansion may befmade to take place either laterally or verticall 'or in both directions.'l v

' Wliat I claim as new, and desire to secure by 'Letters Patent, is-

Alreverberatory furnace provided witn a plurality of successivel llame-introducing means at different points along its hearth--` chamber and of an internal diameter insienes creased beyond each such flamfag-introducingA 3. A. reverberatory furnace provided with 'l ha plurality of fire-boxes feeding its hearthchamber at different successive points along its len th, and of an internal diameter increase beyond each such fire-box. y

4, A reverberatory furnace provided with a plurality of fire-boxes feeding its hearthchamber at different successive points along its length, and with the arch of said hearthchamber stepped up beyond each such firebox.

5. In a reverberatory furnace, means for successively increasing the volume of flame therein, and' means beyond each point of increment in flame volume for increasing the cross-sectional area of the hearth-chamber to correspond to the increased volume of flame.

6. In a reverberatory furnace, a hearthchamber of successively-increasing internalV ameter at a succession of points along its course and provided with a flame-septum at each point of increment.

8. In .a reverberatory furnace,l a hearthchamber havin(r points of successively-increasing internal iameter, one or more flameseptaat points of increment, and one or more fire-boxes opening into the hearth-chamber under said septa.

9. A reverberatory furnace comprising a long hearth-chamber with its roof stepped up at various points along its length to give increased chamber room, a source of llame at IOO IIO

each such point of increased height, a horizontal flame-septum above each inlet for flame and'mechanical means for advancing material through the furnace.

10. A reverberatory furnace comprising a long hearth-chamberwith its roof stepped up at various points along its length to give increased chamber room, a fire-box'opening into the chamber at each such point of in-' creased height, a chimney-stack for the chamber, means for admitting a mixture of Waste gases from the stack and air into each firebox and mechanical means for advancin material through the furnace.

- 11'. A reverberatory furnace comprising a long hearth-chamber with its roof stepped up at various points along its length to give'increased chamber room, a fire-box opening creased height,

opening a flame-septum above the from each fire-box, a chimney-stack for the. chamber, means for admitting a, mixture of Waste gases into each fire advancing 1n from the stack and air -boX, and mechanical means for aterial throngh the furnace.

n Witness whereof I have hereunto set m hand, before two subscribing witnesses, thls 6th day of February, 1905. l

BYRON E. ELDRED.

Witnesses:

CARLETON ELLIS, M. F. MANG-ELSDOBFF. 

